Electrodeposited copper foil is used in a variety of products. For example, it is an indispensable part of printed circuit boards. Double-sided glossy copper foil is coated with an electrode active material and used as the negative electrode plate of a lithium ion secondary battery. Many electronic products therefore rely, at least in part, on electrodeposited copper foil.
A typical device for manufacturing an electrodeposited copper foil comprises a metal cathode drum and an insoluble dimensionally stable anode (DSA), the metal cathode drum being rotatable and having a polished surface. The insoluble metal anode is arranged at approximately the lower half of the metal cathode drum and surrounds the metal cathode drum. An electrodeposited copper foil is continuously manufactured with the device by flowing a copper electrolytic solution between the cathode drum and the anode, applying direct current between these to allow copper to be electrodeposited on the cathode drum, and detaching an electrodeposited copper foil from the cathode drum when a predetermined thickness is obtained.
A typical printed circuit board is manufactured by attaching a copper foil to a substrate such as an epoxy resin-impregnated glass fiber substrate. The copper foil is bonded to the substrate by application of heat and pressure. Upon performing the bonding, portions of the copper foil that are not used for making the circuit connections are removed, for example, with an etching solution such as an acidic or alkaline etching solution.
In order for such printed circuit board to function properly, corrosion and discoloration of the copper foil should be prevented. The prevention of such corrosion and discoloration is currently performed by applying a chromium-based component to the copper foil through chromium plating or chromate treatment. Due to the negative environmental impacts of chromium, an alternative form of treatment for preventing corrosion and discoloration of a copper foil used in a printed circuit board is desirable.